Guillotine
by Starcrier
Summary: Sherlock Holmes has faced countless criminals, each one presenting him with a game, a thrill more addicting than any drug. But when a series of murders breaks out across London, a chessboard is set and a unique challenge is laid before him - one that comes with thrills all its own. Sherlock/OC, set during season three.
1. Prologue

**A/N: Welcome to the madness. :) I have absolutely no idea what I'm doing here. Carry on.**

_Guillotine_

_Prologue_

_Milady, _

_I know you trained us never to correspond with you when we suspected we were being tailed, but I had to warn you. You are in greater danger than we first thought. The situation is escalating rapidly, and what's more I know for sure now that they won't stop until your reign is permanently ended. I don't dare risk putting their identity in writing, but you must know their reach is so much broader than we estimated. _

_Please, Milady, you must protect yourself. Withdraw the informants and stall the operations, or they will find you. They know you are based in London, and were already closing in on you by the time I discovered them, but I managed to corrupt their intel. I hope to meet you at Court as soon as I can shake my pursuer to explain everything. Double the watch and please, for your sake and that of the entire Set, be careful._

_Long Live the Black Queen. _

_Faithfully Yours,_

_~Third Pawn of Her Majesty's Ebony Set._

**~S~H~**

On a typical February afternoon in the heart of London, the blood that traced a path in the cobblestone of the forgotten little alley behind the local greengrocer's went unnoticed.

The sun was hidden by a layer of clouds that painted the sky a dismal grey and infused the air with a chill that kissed the bones, but the busy city just bundled up and kept their heads down against the cold. (They considered themselves lucky it wasn't raining.)

Nobody cared about the abandoned side street, or the pressurized hiss of spray paint escaping its canister that came from within – not at all an uncommon sound for the area.

Nobody heard the soft grunts of exertion or the muffled scrapes of boots on brick.

Nobody noticed the great creak of the rusty fire escape that trembled under its new load.

And then, after a moment, all was quiet again, the stillness just as unheeded as the actions that had taken place moments before.

On a typical February afternoon in the heart of London, a body was hung in the forgotten little alley behind the local greengrocer's.

But by the time it was finally discovered, it was already too late.

**~S~H~**

_Milady, _

_The Third Pawn has fallen. We are under attack. _

_~Knight of Her Majesty's Ebony Set. _

**A/N: ****This _begins between TEH and SOT_, and will continue (probably) through HLV. I** hope you're interested, there's more where this came from! I can't say updates will be frequent, not with my Batman story, which takes priority, or with work or school in the way, but I will do my best to continue it. 

**This will be Sherlock/OC, but it will probably be a slow build due to Sherlock's sociopathic tendencies and my fundamental issues with understanding conventional romance. **

**Also, I don't own _Sherlock_, much to my own disappointment. **

**Don't forget to leave a review! **

**Sincerely,**

**Starcrier. **


	2. Chapter I

**A/N: Yay, you came back for more! Hope you like!**

_Guillotine_

_Chapter I_

Sherlock could tell his brother had arrived outside the flat by the way he slammed the car door: imperiously and with the understanding that it wouldn't be opened again until he himself touched the handle.

Mycroft did everything with an air of powerful finality, Sherlock reflected with a grimace of irritation as he heard the front door open and shut decisively. The older man seemed to believe that nothing he did with his own two hands could ever be undone by anyone of a lower station than himself.

The younger Holmes didn't look up from furiously scribbling notes on an experiment that had just gone fascinatingly awry, exploding all over the kitchen and even splattering a bit on the ceiling. (_Note to self: human kidneys should _not_ be left under concentrated heat for longer than fifteen minutes._)

After the data was properly recorded, the detective straightened from his position at the counter and surveyed the scene around him with an arched, unconcerned eyebrow. If Mycroft was brief, which happened approximately never, he just might have time to clear the mess away before Mrs. Hudson returned from the shops and started whinging about it.

"My word, what _is_ that smell?" Oh, that was Big Brother's voice alright, Sherlock noted without turning as he peeled off his gloves and goggles; it was aloof and just barely disgusted enough to reveal that the scent offended him, without exposing himself to any of the vulnerability of admitting he had olfactory senses.

"Jellied kidney," Sherlock deadpanned, exiting the kitchen and flopping himself down into the armchair across from John's empty one. "What is it, Mycroft? I'm busy."

"Obviously," came the snide response.

His elder brother gave his kitchen a cursory examination, curled his lip in distaste, and promptly focussed all his attention – or as much attention as he was capable of giving while simultaneously running the British government – onto the consulting detective.

"I've a case for you."

"Not interested," Sherlock replied without hesitation, which meant that he was.

"Oh come now Sherlock, we both know you're dying for one. You could even use it as an excuse to call Dr. Watson. You haven't interacted with him in quite some time." This comment, specifically designed as an underhanded way to convey that the elder Holmes was still monitoring his brother – and anyone he associated with – closely, had Sherlock glaring daggers, swords, and even a spear in his direction.

"John is busy, I'm told, with his... medical practice, and his... wedding plans, and... _social life_," he stated the last one the way a person would have said _raw sewage_.

"Ah," Mycroft responded in mock sympathy, settling himself into the doctor's chair, "Well these things do happen to normal people, I'm afraid. They meet someone, get married, devote their whole life to domesticity... a shame it had to happen to the doctor, really."

"Aren't you scheduled for a meeting with the Queen?" Sherlock snapped back, borderline petulant.

"No, but you are."

_That_ got his attention, exhibited only in the raising of a single, intrigued eyebrow.

"I am?"

"Not the one you're thinking," Mycroft stated with a small smirk before tossing the manila folder on the table between them.

Unable to restrain his inherent need to _know_ but unwilling to let his brother see how curious he was, Sherlock lazily reached forward and opened the file. His eyes immediately widened at the picture within.

"Where is this?"

"Old Bond Street, a few blocks away from Berkley Square."

"Why bring it to me?"

"This is the third time it's happened in as many months. The MO is always the same but the... _accessories_, are new."

Sherlock stared into the photograph intently, as though doing so would force it to give up all of its secrets. In the first and most recent picture, the body of a young girl hung from a fire escape in an alley, in her early twenties or late teens, with close-cropped blonde hair and blue, sightless eyes. Spray painted on the already-vandalized wall behind her in prominent white were the words, "Down With the Black Queen", and a black tiara was fixed to the woman's head. She was covered in a robe of the same color, a size too large; blood stained the front from some sort of indistinguishable wound in her neck. The other two pictures were the same in body placement and message, though they were both male and were killed in their own clothes.

"The Black Queen...," Sherlock muttered, searching his mind palace briefly, "A bit of an urban legend, isn't she?"

Mycroft raised an imperious eyebrow.

"So was Moriarty, at one point."

"_There's a name, a name that no one says. And I'm not gonna say it either."_ The detective blinked away the memory and scowled at his brother.

"Why now? Why are _you_ so invested in this?"

Mycroft drummed his fingers on the handle of his upturned umbrella once, quickly, before answering.

"We fear she will retaliate." At Sherlock's stare, he elaborated. "We don't know much about her to begin with. Her organization is all but impenetrable, and we wouldn't even know she existed if things like this didn't happen occasionally. But this... this is unlike anything we've seen before. Someone is targeting her."

"And because you don't know the extent of her power you don't know what the damage will be if she reacts, of course." Sherlock was quiet a moment. "I know I've heard my homeless network mumble about her before. What exactly is she involved in that makes her so dangerous to you?"

"It's not what she's involved in. It's what she has."

"Oh?"

_Not another situation like The Woman, I hope..._

"Control, Sherlock. As far as we can determine, her influence is everywhere. She has a vast underground network, far larger than yours, that spans all of London, possibly beyond; nobody moves in this city without her hearing about it. All our efforts to capture or even locate her have ended in miserable failure. She seems to favor weapons dealing, but despite all this, she's not actively a threat to the peace."

"No, she just has the potential to be. That's why you're so worried about this."

"There is also the fact that someone is running around murdering people, but yes, that would be the gist of it."

"So why not send one of your own peop – Oh, of course. You really _don't_ know who she's controlling, do you?" Sherlock didn't even try to keep the smugness out of his voice. "You don't know who to trust so you came to me. How touching."

"Will you take the case or not?" Mycroft would have growled if it wasn't entirely beneath him to do so.

Sherlock gave him an impertinent grin that had never, not once, failed to grate upon his brother's nerves _and_ drive him frantic with unease at the same time.

"Oh yes. It should be fun. Have the body sent to Bart's, I want Molly specifically to look over it."

Mycroft rose, umbrella in hand and stared down his nose at his younger brother.

"Do be careful, Sherlock. You'll be hunting down two powerful criminals in this case, not just one. This could get... _messy_."

He punctuated his ambiguous warning with a single raised eyebrow, this being the man's sole flag for anything distasteful. Bodily fluids, execution, poor manners – all received the same arched brow.

The detective waved him off, before returning the hand he'd used to gesture with back against his lips, miming a position of prayer.

"Makes it all the more interesting. Give _your_ Queen my love, won't you?"

With a put-upon roll of his eyes, his older brother was gone, and Sherlock was left alone with his thoughts. With a small smile of challenge, the high of the chase already beginning to fill his blood, he picked up the photographs and began to tack them above his couch.

"The game is on, Your Majesty."

**~S~H~**

"Milady, they've moved her body."

"_What?_" the woman's voice was a low growl of warning, at which the man before her knew to take a careful – and inconspicuous – step back.

"The order changed not five minutes ago. They're taking her to a different morgue."

"She was supposed to be in _our_ morgue. Why did they change it?"

"I'm not sure, Milady. Our man inside said there was no explanation given."

With a growl of frustration, the woman paced away, toying harshly with the pendant at her throat. After a minute or two of this, she whirled back around to face him.

"What is Scotland Yard saying about this?"

A shift of unease.

"Nothing at all, Ma'am. There's nothing in the papers, so far as we can tell there's not even an official police report for this murder, and they aren't investigating _any_ of them."

The woman blinked, her fingers curling into her palms.

"That doesn't make sense. These are murders, _serial_ murders, or they would look that way to everyone else. Isn't this supposed to be that idiot Lestrade's division?"

"But isn't it a good thing they aren't investigating, Milady? I thought we didn't want the police involved."

"We _don't_," she snapped, "but that's not the point. This smells like a payoff. Someone has a better handle of the situation than I do and I don't underst – Wait. _Wait_." Her eyes widened and she brought her hands together once in front of her face, making a single clapping noise that rang throughout the shadows.

"What is it?" the man pressed, taking in her more relaxed stance and dangerous smirk. He almost regretted drawing her attention to himself when he saw the perfect, gleaming, borderline cruel clarity that danced within her gaze as she turned it on him.

"Where are they relocating her body? What morgue?"

"St. Bartholomew's, Milady. Why?"

"And how is our dear friend Mycroft Holmes? Has he deviated from his usual routine on this lovely day?"

The man frowned a moment in thought, sent off a quick inquiry on his mobile, and looked back at her.

"Not especially, though he did pay a brief visit to Baker Street. Why, do you think they have something to do with this?"

The woman went quiet for a moment, never drawing her gaze from his, and when she finally spoke her voice shot chills down his spine.

"It seems the angels have reviewed our cause and found it to be worth their time."

"Angels, Ma'am?" Confusion was evident in his tone.

She seemed to snap out of whatever daze she had fallen into and blinked once, before toying with her pendant again.

"Indeed. Have someone watch the morgue, I don't want to lose track of that body. As soon as it is practically possible, I want it retrieved and buried, is that clear?"

"Yes, Milady." And with that, he turned on his heel and left her alone in the shadows.

She paced once, twice, before stepping towards the exit and withdrawing her mobile.

"Well well, Mr. Holmes. It looks like the game is on."

She smiled.

"Your move."

**A/N: "I really shouldn't do this," Starcrier mutters to herself as she clicks the upload button without plotting half the story. **

**I don't have a set path in mind, not yet, it's really more like, "I'm gonna meander aimlessly in this direction and see where it goes" at this point. Whether I update more or less depends on feedback and readership. **

**The Black Queen belongs to me, but _Sherlock_ sadly is not mine. Carry on. **

**Don't forget to leave a review, and special thanks to **Josephina Alex** for reading this in advance and giving feedback! **

**Sincerely,**

**Starcrier. **


	3. Chapter II

**A/N: Welcome back my lovelies! I have actual plot now yay!**

_Guillotine_

_Chapter II_

"So she's like the Gollum. From the case with the fake painting," stated John Watson, ex-army doctor and friend to the Man Who Had None, cocking his head curiously in the confines of the sleek vehicle Mycroft had procured to shuttle them to the crime scene – which at this point was closed to even Scotland Yard. The British government, it seemed, would be taking no chances; the Black Queen's continued anonymity was crucial to maintaining some level of control over London's underworld.

Sherlock, who was seated beside the doctor, wrinkled his brow.

"Only in the sense that she's practically a myth, but there the similarities end. The Black Queen operates in a specific circle of informants, each keeping her up to date on every important action in the city, to manipulate as she chooses. As far as we know, she's not affiliated with any assassins of the Gollum's caliber," he replied, peering out the window every so often as they drove. He had filled John in on everything he knew so far about the case, which at this point wasn't much. He could only hope the crime scene would yield more illuminating results than his brother's files.

The car took a final left and slowed to a halt beside a curb at the opening of a dark alley, situated neatly between a run-down greengrocer's and a shady-looking pub. Without hesitation Sherlock and his companion slid out, Anthea emerging from the passenger seat to join them.

"It's just ahead," she murmured, not looking up from her phone as she lead them forward, nodding at the pair of suits who had taken up stations at the mouth of the alleyway. The incessant clicking of her impossibly-tall heels halted at the crime scene tape that spanned the entrance, and she made a vague gesture – still without looking up – that the two men should proceed without her.

Sherlock did so without a second glance, and John followed, albeit with a lot of mental grumbling about what could possibly be so bloody important on that mobile of hers.

The distinctive, high-pitched sound of squeaking rats dogged their footsteps as they drew further and further into the darkness, the light of the day blocked out by the looming buildings above their heads.

"Blimey. Good place for a murder, this," John muttered beneath his breath, taking in the refuse and graffiti.

"But the point was to be seen; they wanted the message to get out so why do it all the way back here?" Sherlock wondered, taking out his pocket torch and sweeping the walls with it for a better look. His light gradually landed on the rusty fire escape and, consequently, the bloody rope that dangled from it.

"You thinking what I'm thinking? About the rope?" John murmured, stepping closer to inspect the object in question.

"It wasn't the cause of death, yes, I'd suspected. We won't know until Molly gets done with the autopsy, but it looks like her throat was cut first, judging by the amount of blood," Sherlock responded, turning the light to the stained crimson cobblestone beneath their feet, before inspecting the wall where the message was scrawled in white.

"'Down with the Black Queen'," John read aloud, cocking his head. "You'd think she was actual royalty, the way they're talking. Like they're trying to overthrow a real queen."

Sherlock froze, staring off into the middle distance before turning back to face his friend and the rope in front of him.

"They _are_ acting that way, aren't they?" he murmured softly, before silently beginning to pace, heedless of the garbage that crunched and scattered beneath his shoes.

John shifted his stance, trying – and failing, as he always did – to make the same connections as his companion. After another moment of this, he made an exasperated noise in the back of this throat and crossed his arms.

"Yeah, alright Sherlock, care to explain to the rest of the class what's going on?"

The detective rounded on him, icy eyes gleaming.

"When someone attempts to overthrow a national leader, it's a largely impersonal affair. You either do it to gain power or because the leader is _abusing_ their power. You don't know them very well, you don't make personal shots. But this," Sherlock made a grand gesture that encompassed the whole crime scene, "this is _very_ personal. Someone wants The Black Queen to bleed."

"So now what?" John asked as his companion took one last sweeping glance around the alley and strode back towards the street.

"We need to find out who this woman was, what she meant to the Queen. They wouldn't have just done this to any person on the street; there has to be a connection somehow," Sherlock responded absently, his eyes flicking back and forth in front of him as his mind raced to find answers.

The pair of them ducked beneath the tape again and entered the car, Anthea trotting swiftly behind them.

"Take us to Bart's Hospital," the detective commanded, leaving no room for argument, and the car pulled away from the curb only moments later.

"So? Why the alley?" John pressed as the car merged back into traffic.

"The Queen has a penchant for theatrics, and whoever's targeting her must be playing the same game. All the bodies were hanged in poor, obscure locations, but this one was the most foul, likely because she's a woman," came the reply, and John furrowed his brow in thought.

"What's that got to do with it?"

Sherlock gave a sigh of extreme impatience.

"_Think_, John. They put her in robes and placed a black crown on her head. She's a surrogate. Whoever did this didn't want anyone to think that the _organization_ was being targeted; it's the Queen herself they're after."

"So whoever it is is toying with her," John clarified, earning himself a nod from the detective, "but who would do that? If she's as powerful as you say, who'd dare pull off something like this? Who would even have the means?"

Sherlock turned his gaze back out the window, watching the city whirl by him in streaks of grey.

"That, John, is the question I intend to answer."

**~S~H~**

Molly Hooper was absolutely, completely, and most unquestionably _over_ Sherlock Holmes. She _was_. Tom was sweet, and affectionate, and attractive, and hadn't just disappeared for two years without a single word of reassurance that by helping him fake his death she hadn't just killed him again –

No. None of that mattered now. Sherlock was safe, and back in London, and planted firmly in her friend zone, thank you very much.

So if her heart skipped several beats when he swept into her lab like nothing at all had changed between them – and perhaps to him, nothing had – it was in a completely platonic, non-interested sort of way. Really.

"Hello Molly," he greeted as John trailed in behind him, his voice rich and deep as it always was, and mercifully lacking the manipulative purr he'd used on her before the fall. Come to think of it, he hadn't used that tactic at all since he'd been back, and she felt a secret thrill at the reminder that maybe he really did see her as an equal, or perhaps – dare she think it – a friend?

"Hello Sherlock," she responded, her cheeks warming without her permission as she turned back to the body before her, compulsively adjusting the sheet that covered the dead girl's nude form.

"What have you found?" he asked, all business – nothing new there – but at least he wasn't thoughtless about it anymore. (No longer being reduced to a stuttering mess at the sight of him was also a plus.)

"The cause of death was blood loss, a severed jugular. She was hanged post-mortem; there's no bruising around the injury, see?" she pointed out, gesturing to the wound.

"It's very clean," John observed, leaning over the body, and she nodded.

"The killer would have used an extremely sharp knife. It's rare to see a cut that neat without medical experience of some sort, but that's not the case here. It was done too fast; the skin around the laceration folded back a bit, see? No medical training, just a professional... erm, person who does this a lot." She cringed, tracing the air above the injury with her index finger before glancing back at Sherlock, who was examining the woman with alarming intensity. His gaze traveled over the stitched V in the center of her chest, sliding across the odd scar or two he found on the skin there, and shifting once more to her arms. His brow furrowed.

"She was a heroin addict. Needle tracks."

"Well yes, but the tox screen came back negative. She was clean, and I'd say she had been for a while. Those marks are old," Molly replied, before continuing on, "There are few defensive wounds, all minor, which is odd. She was definitely strong enough to have fought back."

Sherlock glanced back at John, who met his gaze evenly.

"Ambushed." Whatever else he was about to say was interrupted by the chime of a mobile suddenly ringing from his coat pocket, and he quickly withdrew it, eyes widening as he took in the new information.

"Her name was Sylvia Hale, age twenty, born in Brighton, ran away from home at sixteen. She drops off the radar there, no more records of her."

"Until now," John murmured as Sherlock pulled up a photograph he'd received from who knew where – Molly thought it best not to question these sorts of things, not when his brother was involved.

Displayed on the screen was the image of a blue-eyed girl with long brown hair and sharp cheekbones. It was a school picture, but she wasn't smiling, and her gaze seemed more haunted than happy.

"She went to lengths to disguise herself, so she knew that what she was doing would draw the wrong kind of attention. But just how involved were you?" Sherlock directed his question to the girl on the table, turning his gaze back to her scalp, where the dark roots of her peroxide-blonde hair were just starting to show. He traced his eyes across her forehead and behind her ear – and then sucked in a sharp breath of surprise.

"What is it?" John asked as the detective reached to push a lock of hair out of his way. Molly peered over his shoulder to look – it was a black tattoo, imprinted just behind the shell of her ear, so small she'd nearly missed it.

"It's a pawn," John stated in confusion, "Does that mean something?"

Without answering, Sherlock straightened and stared back down at his phone, fingers flying as he typed.

"Did she have any other tattoos?" he questioned, and she shook her head only to realize moments later that he wasn't looking at her.

"No, none."

"I need to find out if the others were reported with a mark like that."

"Others?" Molly asked, looking through her paperwork, and Sherlock nodded at her distractedly.

"Two others, both men, killed the same way. Their bodies were processed in a different morgue."

"Is this not Scotland Yard's case?" She was confused now; most of the Yard's bodies came through her.

"No, it's Mycroft's. This is all supposed to be very secretive, apparently." This was stated with no small amount of derision, and Molly nearly laughed at the look of disgust on his face. He was always thrilled to take cases where a murder was involved, but the mere thought of his brother took some of the excitement out of it for him. She turned away to hide her smile.

"I need to get back to Baker Street, review the histories of the victims again. With any luck my _brother_," he sneered the word and she rolled her eyes with amused exasperation, "can tell us if the others had tattoos. Thank you Molly, excellent work, goodbye now." And with that he was gone, exiting the room with characteristic grace. The pathologist watched him walk away, still not used to being thanked by the object of her non-affections. (The "non" was very important here.) Whether or not he openly acknowledged it, things _had_ changed between them the day he'd asked her to fill in for John. Some deeply-buried part of her regretted that it only happened _after_ she got engaged.

She bid John goodbye as he followed his companion out, waiting until the door swung shut behind him before turning back to begin cleaning up.

She had a date with Tom tonight; she didn't want to be late.

**~S~H~**

"Milady, Mr. Holmes has left the hospital. He's definitely taken the case." The man's voice echoed through the dimly-lit court, directed at the woman who was pacing at the front of the room.

"Good," she replied without stopping, "you know what to do with the body."

The man nodded and moved to obey, only to be halted by the woman's next command.

"Contact him."

He stopped suddenly, eyes wide, before turning back to her.

"_Him_, Milady?"

"Yes."

"Are you sure? He said he wasn't to be disturbed unle –"

"Unless what?" she snapped suddenly, whirling on him, "Unless it was an emergency? Someone is _killing_ members of my Set and I can't track them. Once is coincidence, twice is the job description, but this... this is deliberate and I can't ignore it anymore. I need his help. Contact him, and do it quickly."

The man ran a hand through his hair in uncertainty, but nodded just the same.

"Yes Milady," he bid as he disappeared from the room.

The woman stared after him, trying to ignore the feeling that her grip on the world – which had been so secure mere days ago – was now slipping through her fingers.

Her fist clenched. That wasn't an option.

If she fell, she was taking London down with her.

**A/N: So, I couldn't resist putting in a little one-sided Sherlolly, since it's normally my OTP. However, this will not be a trend, nor will there be any Molly bashing. Next chapter we'll see the plot start to pick up even more, and add an interesting twist to our tale. ;)**

**Hope you enjoyed, and don't forget to review! Tell me, what are your speculations about Sylvia Hale's death? The killer? The mysterious "Him"? Let me know your questions; it tells me you're interested! **

**The Black Queen belongs to me, but _Sherlock_ sadly is not mine. Carry on. **

**Special thanks to **BadWolfSonnets **and** ** for reviewing this chapter in advance, and thanks also to: **AssassinsCreedFAN, OpalFyr, thirteen-yellow-roses, abubblytale, Navatii**, and my three **Guests** for reviewing! Thanks also to those who fav'd or followed! **

**Don't forget to review!**

**Sincerely,**

**Starcrier. **


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